diff --git a/src/wp-admin/theme-editor.php b/src/wp-admin/theme-editor.php
index f5b789e..84cf37e 100644
--- a/src/wp-admin/theme-editor.php
+++ b/src/wp-admin/theme-editor.php
@@ -192,7 +192,7 @@ if ( 'POST' === $_SERVER['REQUEST_METHOD'] ) {
 	</div>
 <?php endif; ?>
 <?php if ( preg_match( '/\.css$/', $file ) ) : ?>
-	<div id="message" class="notice-info notice">
+	<div id="message" class="notice-info notice is-dismissible">
 		<p><strong><?php _e( 'Did you know?' ); ?></strong></p>
 		<p>
 			<?php